Continuously Variable Transmissions (CVT)

What is a CVT? A continuously variable transmission (CVT) is a transmission which can change steplessly through an infinite number of effective gear ratios. This allows the motor to putout the proper amount of power improving on efficacy of traditional transmissions.

Types of CVT’s Variable-diameter pulley (VDP) or Reeves drive Toroidal or roller-based CVT Infinitely Variable Transmission (IVT) Ratcheting CVT Hydrostatic CVTs Variable toothed wheel transmission

Possible Markets for CVTs Automobile Heavy industry Oil production Wind Energy technology

Automobile applications Most major automobile companies have already started experimenting with CVT technology. Can adapt to older vehicles with traditional transmissions. Claims of a 20% gain in fuel economy compared to past transmission technology.

Heavy industry Applications Fully adaptable drive system for industrial Land Vehicles. Adjustments and maintenance made easer through smaller parts and computer monitoring technology.

Oil Production Could reduce Power costs by allowing motors to maintaining constant loads. Testing will show actual results. Right now its only speculation.

Wind Energy technology Allows for a Possible 3.5 speed increase, allowing for a increase in efficiency. Prevents over speeding of fan blades. REDUCED COST! Using CVT technology can reduce the cost of a wind turbine by about $80,000

Possible Competition Continuously Variable Drive – Controls Electric motors up to 10hp, low threat. Other New Experimental Transmissions- Fuzzy Logic Is being applied to Old transmission technology. Still experimental. Traditional Gear box transmissions. Other CVT manufacturing companies

CVT Draw Backs Becomes Jerky in automobile applications at slow speeds. Intricate parts with high material cost. Examples of materials in CVT, Silicon Nitride, Silicon Carbide, Electroless Nickel, Electroplated Nickel New technology so there are limited people that understand the operations with in a CVT.

Advantages CVTs can compensate for changing vehicle speeds, allowing the engine speed to remain at its level of peak power and efficiency. This improves fuel economy and reduce exhaust emissions. There are 25% fewer moving parts to a CVT transmission. Cheaper on wind power applications. And can prevent damage from high winds.

Conclusion This technology is still experimental, although some companies have proven that CVT are practical. With proper funding for research it is possible to create a CVT to satisfy each of the four categories listed.

Works Cited &wo= &DISPLAY=CLAIMS Assessing the Potential of a Mechanical Continuously Variable Transmission for Wind Turbines, National Renewable Energy Laboratory, J. Cotrell, 2005